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Here is a shot taken the same night but in Ha.
Exposure 10 minutes binned 2x2.
All other 11 Ha frames looked about the same.
Notice that there are not 2 lines but there is still a twisted rope effect? -
the extended spikes get dimmer then brighter.
This view is at 200% where as the first was at 100%.
The other stars do look more in focus.
Notice that the camera must have rotated as the companion
star of Alnitak is now inside a diffraction spike.
The focus was changed for Ha as it's different to the LRGB filters
which are supposed to be all parfocal.
The seeing was about 3 arc seconds & the guiding inside 0.33 pixels rms.
Ignore those hot pixels.
Question - was this one correctly focused?
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